Growing Peaches in the Greenhouse
Peaches and nectarines are ideal for growing in a lean-to greenhouse where they can be trained on the back wall, the growths being tied in to horizontal wires set 9 to 12 in. apart. Both these fruits are suitable for growing in unheated and cool greenhouses (heated to a temperature of 10°C. [50°F.]) but there are certain disadvantages in growing them in a house shared with other plants which need more than modest amounts of heat in winter for the heat can excite the trees into premature growth and cause bud dropping. In an unheated house they rest during the winter and only start into growth when the weather improves in early spring.
I consider one of the best peaches for the greenhouse is the self-fertile Peregrine which starts ripening from early August onwards in an unheated house and a little earlier in a heated one. Hale’s Early is another good variety but it needs another variety near it for pollination purposes. My choice of nectarines is the yellow-fleshed Pine Apple and Humboldt. These ripen late in the season, in late August, September and early October. A mature fan-trained tree will virtually fill the wall of an 18 ft. lean-to greenhouse.
Peaches and nectarines need a reasonably rich deep soil and it is advisable to dig out the existing soil in the border to a depth of 2 to 2-½ ft. and spread a 4- to 6-in. layer of broken bricks, broken flower pots or weathered ashes over the bottom of the border to secure good drainage. Then add a layer of upturned turves, a layer of well-decayed manure and finally rich loamy soil to which the coarsest grade of bonemeal has been added at the rate of 1 lb. to each barrow-load of soil. This mixture should be made firm and the trees planted so that they are at the same depth as they were in the nursery. The soil mark on the stem will indicate the correct depth for planting.
The trees are grown as fans and a young tree when purchased will normally have six or eight branches trained in the shape of a fan. These are tied in to bamboo canes to give even coverage of the wall.
Note that peaches and nectarines bear fruit on the previous year’s wood, and that there are two kinds of buds – round fruit buds and pointed growth buds. The former cannot produce shoots.
In the spring, as the young shoots begin to develop, disbudding is important if the tree is to keep its shape. All badly placed shoots must be rubbed out; these include those growing towards the wall. Those growing out from the front of the branches, and those growing on the back of the branches. The remaining shoots should be thinned so that they are spaced 12 to 15 in. apart, and these will be sufficient to form a well-shaped tree with plenty of fruiting branches the following year.
All shoots should be tied in to the training wires as they develop, so that the fan shape of the tree is maintained.
Winter pruning consists only of cutting out old or diseased branches where necessary.
Watering and Feeding
As the roots of a peach or nectarine grown in a greenhouse border are closely confined, watering is necessary at frequent intervals during spring, summer and autumn. I allow a free-flowing hose-pipe to run on to the bed for anything up to two hours, moving it along at intervals.
Feeding is essential once the tree is established. It is not wise to feed in the early stages as the tree would become too vigorous but once it has begun fruiting feeding should be carried out in the spring, top-dressing the bed first in late winter with John Innes No. 3 Potting Compost. I use a general purpose fertiliser applied at the rate of 4 to 6 oz. per tree and water this in well.
Peaches and nectarines grown under glass must be assisted with their pollination. This is best done with a rabbit’s tail attached to a bamboo cane. A piece of soft cotton wool on a cane or a small camel hair brush. Pollinate the flowers about midday when the pollen is dry, just touching the flowers to transfer the pollen from stamens to stigma. This should be done every day while the trees are in flower as the pollen does not all ripen at the same time. After pollination, the humidity of the greenhouse should be raised by damping down the floor and lightly spraying the trees. Close the ventilators for an hour or so after this.
Often more fruits are set than the tree can carry without reducing its vigour and the size of the following year’s crop. These should be thinned, but not until stoning is completed. When the fruits are about the size of walnuts and have been stationary for about three weeks, this stage can be assumed to have been reached. Where two or more fruits are clustered together reduce these to one, and when the final thinning is done leave only one fruit to every 9 to 12 in. of branch. Watering and feeding should be increased at this stage. Pest and
The main pests are aphids, red spider and scale. Aphids can be controlled by sprayirg or fumigating with BHC, red spider with sprays of clear water or white oil emulsion, and scale by spraying with a winter wash of DNOC. The main disease is peach leaf curl. Remove the infected leaves and twigs and spray with Bordeaux mixture at bud burst.
- Growing Red Currants (diyinfozone.com)